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Old 09-05-2019, 06:48 AM   #38
The Radium King
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Join Date: Apr 2010
Location: Canada
Posts: 3,121
sure. you are lucky - your car is a 2003 so the anniversary edition tune will work on it. for a mechanic with a pst2 that knows what he is doing it is a 5 minute job to push the new tune onto your car. you would need the dme programming code for your car but any dealer should be able to provide that. otherwise a custom tune or run w the original maf holder. at a minimum, you can run with the original holder until you can get the new tune. for the cost of a custom tune i'll fly to sweden with my pst2 and tune your car for you (actually, i will be in france in april, perhaps i can do a side trip ...).

1) i think you have this correct.
2) i am not sure about this, but that's my thesis. given that the intake runners (the six legs that descend to each intake valve) should also be of decreasing diameter to accelerate air into the cylinder (look at any car design, even the venturi intake tubes on old itb cars). however, if the air acceleration is happening in the intake runners, what is the need to accelerate air into the intake plenum? i'm not sure, so my intake does both.
3) longer runners mean more acceleration, but also more air resistance (work). so, short fat runners are good for hp (less resistance) while longer ones are good for torque (better cylinder fill). 986 is short and fat, while 996 are longer. unsure why the difference; perhaps engine bay packaging, perhaps efforts to limit performance of the 986 vs 996. nova has 996 runners on his car and swears his 3.2 pulls as hard as his 3.4 with all the above modifications. remember, porsche limited the 986 vs the 996 to avoid one stepping on the other; given heads and internals are the same (only displacement differs, but differences in hp/litre ratios between the two engines indicate more than a difference in displacement is at work) so porsche could only limit the 986 w exhaust, intake, and tuning.
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